Getting things to stick to your handlebars

I have some lights and a horn to put on my handlebars (I commute in a large city), but even when I screw them as tight as I can, they do not stay, especially over bumps. Can I superglue them, or is there some other way to make them stick and stay firm?

rubber inserts for headlights

the BV headlight set I got included rubber inserts that help keep them in place. pretty good deal at about 11 bucks. if you don't want to get another light, then try finding something rubbery, or maybe try winding a rubber band under the mounts.

You could take an old inner tube and build up the bar area a bit before you install the clamp. Also the idea of hanging the light under the bar instead of on the top is a pretty good solution if you can keep the cables out of the way.

Don't you hate it when a sentence doesn't end the way you think it octopus?